So now, recently wowhead added the nifty feature of sortable columns listing the stats you filtered on. Now I'm sure the basic stats already work fine for this, but as a healy priest my upgrade links use the "Healing item" filter, which gets no column. Here is an example. Now, if you were to also include conditions for the other stats I would care about so they can be sorted against, that would rock! This is simple to do, just add a ">= 0" filter for the stats in question. Here is the same search, but with the added columns.

Since wowhead.com initiated the built-in weighting system it might be easiest to use the pre-fabricated ones. Grab the current spec and have it querry wowhead using those pre-defined factors. So instead of what you made up for it wowhead would give you this Weighted Result.

Edit: The only times where this may become a problem is when wowhead has multiple prefabricated specs for different talents. I.E. feral druids get "Fearal Tank" and "Feral DPS" on wowhead.